title: Lectin-induced increase in clonogenic growth of haematopoietic progenitor cells.
abstract: The galactoside-specific plant lectin, Viscum album agglutinin (VAA-I) increases cellular parameters of natural host defence. It also binds to a variety of haematopoietic cells, including progenitors. We investigated whether VAA-I has a stimulatory effect on haematopoietic progenitor cells. Peripheral blood progenitor cells from 7 healthy volunteers were cultured in a colony assay with VAA-I plus erythropoietin (EPO) and stem cell factor (SCF). At 50 pg/ml VAA-I induced a significant increase in the cytokine-dependent clonogenic growth (52% in median, p < 0.05). In another set of experiments purified CD34+ cells were isolated from the bone marrow aspirate of 4 patients with non-metastatic breast cancer using fluorescence-activated cell sorting. Binding to CD34+ cells was demonstrated by using directly fluorescence-conjugated VAA-I. Co-incubation with D-galactose significantly abrogated this effect. CD34+ cells were cultured in the presence of EPO, SCF, interleukin-3, granulocyte/monocyte colony-stimulating factor and granulocyte colony-stimulating factor. VAA-I alone had no measurable effect on the clonogenic growth of the isolated cells. However, at concentrations of 100 and 250 pg/ml VAA-I increased the cytokine-dependent proliferation and differentiation of CD34+ cells by a median of 75 and 85%, respectively. The results show that VAA-I binds to haematopoietic progenitor cells and has a co-stimulatory effect on their proliferation.
authors.affiliation: Department of Haematology and Oncology, University of Göttingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Vehmeyer
authors.forename: T
authors.initials: T
authors.lastname: Hajto
authors.forename: K
authors.initials: K
authors.lastname: Hostanska
authors.forename: S
authors.initials: S
authors.lastname: Könemann
authors.forename: H
authors.initials: H
authors.lastname: Löser
authors.forename: R
authors.initials: R
authors.lastname: Saller
authors.forename: B
authors.initials: B
authors.lastname: Wörmann
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D001943:Breast Neoplasms / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D002999:Clone Cells / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D037102:Lectins / Q000494:pharmacology*; D014784:Mistletoe; D037121:Plant Lectins; D028321:Plant Preparations; D010940:Plant Proteins; D010946:Plants, Medicinal; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D018952:Antigens, CD34; D037102:Lectins; D037121:Plant Lectins; D028321:Plant Preparations; D010940:Plant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological; C009674:ribosome inactivating protein, Viscum